Add documentation about supported features

Author: geoffp

README.md

@@ -1,4 +1,12 @@
-## The Handlebars engine for Pattern Lab / Node
+# The Handlebars engine for Pattern Lab / Node
 
 To install the Handlebars engine in your edition, `npm install patternengine-node-handlebars` should do the trick.
 
+## Supported features
+- [x] [Includes](http://patternlab.io/docs/pattern-including.html)
+- [x] Lineage
+- [x] [Hidden Patterns](http://patternlab.io/docs/pattern-hiding.html)
+- [x] [Pseudo-Patterns](http://patternlab.io/docs/pattern-pseudo-patterns.html)
+- [x] [Pattern States](http://patternlab.io/docs/pattern-states.html)
+- [ ] [Pattern Parameters](http://patternlab.io/docs/pattern-parameters.html) (Accomplished instead using [native Handlebars partial arguments](http://handlebarsjs.com/partials.html))
+- [ ] [Style Modifiers](http://patternlab.io/docs/pattern-stylemodifier.html) (Accomplished instead using [native Handlebars partial arguments](http://handlebarsjs.com/partials.html))